toggle_images.py

#!/usr/bin/env python""" toggle between two images by pressing "t"The basic idea is to load two images (they can be different shapes) and plotthem to the same axes with hold "on". Then, toggle the visible property ofthem using keypress event handlingIf you want two images with sifferent shapes to be plotted with the sameextent, they must have the same "extent" propertyAs usual, we'll define some random images for demo. Real data is much moreexciting!Note, on the wx backend on some platforms (eg linux), you have tofirst click on the figure before the keypress events are activated.If you know how to fix this, please email us!"""from pylab import *
# two images x1 is initially visible, x2 is not
x1 = rand(100, 100)
x2 = rand(150, 175)
# arbitrary extent - both images must have same extent if you want# them to be resampled into the same axes space
extent = (0,1,0,1)
im1 = imshow(x1, extent=extent)
im2 = imshow(x2, extent=extent, hold=True)
im2.set_visible(False)
def toggle_images(event):
'toggle the visible state of the two images'if event.key != 't': return
b1 = im1.get_visible()
b2 = im2.get_visible()
im1.set_visible(not b1)
im2.set_visible(not b2)
draw()
connect('key_press_event', toggle_images)
show()